The rapid increase in the number of users of electronic mail and the low cost of distributing electronic messages, for example, via the Internet and other communications networks has made mass marketing via electronic mail ("e-mail") an attractive advertising medium. Consequently, e-mail is now frequently used as the medium for widespread marketing broadcasts of unsolicited messages to e-mail addresses, commonly known as "spam."
Electronic mass marketers (also called "spammers") use a variety of techniques for obtaining e-mail address lists. For example, marketers obtain e-mail addresses from postings on various Internet sites such as news group sites, chat room sites, or directory services sites, message board sites, mailing lists, and by identifying "mailto" address links provided on web pages. Using these and other similar methods, electronic mass marketers may effectively obtain large numbers of mailing addresses, which become targets for their advertisements and other unsolicited messages.
Users of Internet services and electronic mail, however, are not eager to have their e-mail boxes filled with unsolicited e-mails. This is an increasing problem for Internet service providers (ISPs) such as America Online (AOL.RTM.) or Microsoft Network (MSN.RTM.) and other entities with easily identifiable e-mail addresses such as large corporations (e.g., IBM.RTM., Microsoft.RTM., General Motors.RTM., etc.). ISPs object to junk mail because it reduces their users' satisfaction of their services. Corporations want to eliminate junk mail because it reduces worker productivity.
Accordingly, there is a need for a system that automatically and efficiently identifies unsolicited e-mails messages and controls the delivery of these messages to users, for example by preventing delivery of the messages to the users' in-boxes, identifying the messages as unsolicited messages by displaying the messages in a distinctive display mode, or otherwise controlling the delivery of such messages to the users.